I recently purchased a F150 4x4 with a 4.6 L engine. I purchased the "mandatory" Haynes manual for the truck. The first item I noticed is that there are two manufactures of the 4.6 L engine. One is manufactured in Romeo and the other in Windsor. Does anyone have knowledge of the reliability and quality differences between the engines? Simply put, is one engine better than the other?

 

Starting late 95 Ford used two different versions of 4.6 mod motors. I believe now the W motor is the only one in production (W as in Windsor not the vin code)
First, the Romeo, in cars and trucks starting in late 90, first made with an AOD bellhousing pattern, changed in early to mid 91 with the AODE style bellhousing pattern. All 91 and 92s had smoking problems due to the valve stem seal design. Redesigned for 93, still not right, at about 100k smoke. Redone again for 94, still not right. Then came 95s with different heads, still a Romeo block. Better but will still consume oil with high miles.
Late 95 early 96 and starting production of the new 97 F series, still using Romeo motors, mainly in trucks, I have seen smoking in as little as 50k miles. The passenger cars starting using the Windsor motor in 96, I have yet to see one smoke even up to 300k miles.

Similarites:
both a 2 bolt cross bolted cast iron block with aluminum heads.
Differences
R-has jackscrew centering screws for the main caps, and a one piece thrust bearing (top and bottom)
W-has dowels for centering the main caps and a 3 piece thrust bearing.
R-uses mulitple cam bearing cap bridges, and round springs.
W-has a one piece bearing cap(supposedly) for the cam and oval valve springs
R-has 11 (I think) bolts on the right valve cover
W-has 14 on same cover
R-slower, tends to have detonation problems, more a cause of the oil use, and software
W-runs smoother for the most part, more power from head refinements.
Some other differences, exhaust manifold changes from bolts to studs in late 94. EGR and intake changes from 95 to 96, cars use a sometimes troublesome plastic intake manifold, the trucks use a half aluminum half plastic manifold.
Not sure, but the W and R water pumps although they look the same, don't interchange, I have met up with this one.
The Windsor motor should have a W stamped on the head near the front of the motor.
I would get the Factory Ford manuals by Helm. They are MUCH more comprehensive and the haynes and others are sometimes inaccurate.

 

Sorry I rechecked my bulletins and have to correct a couple of things:
The R uses the two bridged cam caps with a head reservoir for oil.
The W uses individual caps and no reservoir.
The vin code for a W motor is a 6 and the R is a W.
The W has larger main caps and bearings and larger rods with full floating pins and different pistons. (less friction)
The W is not stamped in the head, its embossed on the cam cover near the sprockets.
There are also differences in how the cam sprockets mount to the cams.
And alot of the parts are not interchangeable.

 

>Sorry I rechecked my bulletins and have
>to correct a couple of things:
>The R uses the two bridged
>cam caps with a head reservoir
>for oil. The W uses individual
>caps and no reservoir. The vin
>code for a W motor is
>a 6 and the R is
>a W. The W has larger
>main caps and bearings and larger
>rods with full floating pins and
>different pistons. (less friction) The W
>is not stamped in the head,
>its embossed on the cam cover
>near the sprockets. There are also
>differences in how the cam sprockets
>mount to the cams. And alot
>of the parts are not interchangeable.
>

Fred,

Very good information. Thanks for your response.